Container made of paper



March 23, 1937. M. E. GAZETTE CONTAINER MADE OF PAPER Filed Dec 9, 1933 01,144 y'all/4'12 Patented Mar. 23, 1937.

IUNITED' STATES PATENT "OFFICE.

2.014.899 CONTAINER MADE OF PAPER Marshall E. Gazette, Boston, Mass., assignor to Boothby Fibre Can Company, Boston, Mala, a corporation of Massachusetts Application December'9, 1933, Serial No. 701,633

4Claim8.

This invention relates to improvements in containers made of paper. More especially it relates to containers of the cylindrical paper can type, and particularly to improving the wall structure thereof, and the cover-cap closures for fltting removably over the mouth of a can body.

Cylindrical containers of the general class to which the invention relates are ordinarily made of a tube of paper board permanently closed and sealed at one end in any suitable way, as bye crimped-in closure disk. Covers are made likewise, a short tube constituting a flange of the cover, enclosing the top of thecan body. Such cans are often desired-to serve as accurate measures of contents, as when used for holding liquids,

as beverages, or semi-liquids, powders, etc. This is easily possible if the measure be effected by a filling flush with itstop edge. Therefore, it is particularly desirable that the cap closure be'applicable easily, and without danger of spilling" any of the contents; yet when applied the cap must be tight against seepage of liquid; and it should be able to prevent leakage even when not fully seated, as when contents are somewhat heaped. Also it is important that air or other gas, which may be entrapped when the cover is edge; and the one edge obstructs the other.

The invention eliminates the bringing together of two close fitting raw cut edges, making one of the edges smoothly rounded by a doubling inward of the tubular stock. On a can of ordinary construction, cylindrical from bottom to top, with the deubling applied to the cover, this proves to be not appreciably more prominent than where a single-thick cover flange hugs tightly a singlethick rim portion of can.

It also provides a one-way passage in the cover for vent and harmless escape of gas under pressure, which may become entrapped or. which may accumulate within a capped container.

And it provides a cover-flange wall whose inner fold and interior surface have been reorganized and exercise a cushion-grip, assuring a liquidtight engagement of the flange aroundthe bodytop. 7

It is an important feature that well-known operating methods, and machinery now available, can do whatis requisite. I; further step for completing the cover comprises merely the slitting 'oftheexteriorwalloftheflange'atoneormore strategic locations. The short length of tubular stock taken for the making of the cover flange has to be longer thanhas been customary for. a single-thick cover flange. The can body may be oi an usual construction and its cylindrical walls may be single-thick from bottom to top; but with a cover'as described the top raw edge of the body becomes unobjectionable.

However, if the body-wall be in-turned the customary single-thick raw edged construction of cover flange becomes unobjectionable. In this case the body wall acquires certain special advantages. The doubled wall may house, covered within its two folds, a layer of specialpurpose material which it is desired not to expose. This .material might be some form of heat insulation,

or a special paper such as southern kraft which has strength but is not sightly; or the doubling may eliminate need for a finish layer on the wall stock. In this construction the body wall is smooth and of finished aspect without there being any exposed rawv edges. The extra stock and strength attained -may give 7 such qualities of permanence that the limitation of the paper can to single service usage may be considered removed, and the paper can cup or other utensil may thus enter the class of dishes suitable for repeated use.

1 According to the invention a length of the tubular stock is turned inward forming a doublethick cylindrical flange or wall with a rounded fold at its edge. Ihave discovered that in the case, for example, of such a coverapplied to a raw-edged single-thick body wall, there is thus attained an ease of application like that of a loose cover, yet the cover proves to be equal or superior to covers that are tight, as regards security of position, closeness of fit, and nonleakage.

The cover may consist of a closure disk to which-is crimped or otherwise secured the inturned short tube which constitutes the flange.

.Preferably, the inturned raw cut-edge of the tubular stock of this flange will be tucked loosely into the crevice at the crimp, at the disk end of this short tube. Gases can then pass around this end and into the annular crack in the midst of. the double-thick flange wall, to where a slit or slits through the outer thickness of the double flange wall permits escape -of these gases, if under pressure, although air at 'atmospheric-pressure has little or no ability to enter. I j It is'one feature that the smooth and tight organization of flbres in the paper stock of the in-turnedflange wall becomes somewhat loosened by the sharpness of its in-turning, so that its fibrous structure thus acquires cushioning characteristics whereby the flange engages thecan rim with adequate closeness notwithstanding that themouth of the cap time maybe of size to l and this'adds to the effect from the fact that the stock yields slightly, but it does in fact appear to have a close flt, which gets provely ti hter as the cap is pressed to its seat.

5 It is intended that the patent shall cover, by

suitable expression in the appended claims, whatever features of patentable novelty exist in the invention disclosed.

. In the accompanying drawing:

Figure 1 is an elevation of a cylindrical paper can body, and of a flanged cover-cap closin'e therefor, both embodying features of the invention, portions being broken away to medial section;

'15 Figure 2 is an elevation showing a cover like thatofl 'lgure iseatedonacanwhosewallis only single thick, with portions .broken away for clearness; and

Figure 3 is an elevation of a modifled cap structure, in medial section, showing a cap disk which may be lifted out of its flange.

Referring to the drawing, the can body ll may be the usual single-thick cylindrical tube of helically wound paper, as in Figure 2, in whose bottom end a permanent closure disk (not shown) may be crimped or otherwise secured for serving as the bottom of the container. Such a helically wound tube comprises a plurality of plies of the paper stock, but this composite structure acting as a unit, however it may be internally composite, is herein referred to, for convenience, as single-sheet-thick" stock, by contrast with instances such as in the cover flange, or in the body in lflgure 1, where one such composite thickness is laid over upon another compodte thickness, and the two are described herein as "double-thick". And, in the present case, where the stock is folded up0n itself, thicknesses may bereferredtoastheinnerlimbandtheouter limb of the double-thick stock, the inner limb beinsnearertheaxisofthecontainerbody.

Thein-turningofportionlimaybe 55 complishedbytheumal-dieas thefolding,in aofslishtwrinkles .creasesIlinthein-turnedstock. 'lheseean beseenestendingindirectioninteriorlyoftheflange. Theymakeasnem ofri mmiminwardtowardtheafls amasseto a very slight extent; and as the inmost surface of the in-turned layer has a circumference substantially less than that of the exterior of the double-thick flange, which was originally its own diameter, there doubtless is a thickening of this layer of flbrously loosened paper stock. The whole elect is that of a cushioned surface at the interior of the flange; The fold 22 itself constitutes a. smooth, rounded enlargement of diameter of the inner layer.

The nicely rounded and flnished flange edge 22 is important in that it facilitates the entrance of a raw cut edge of thecan lip into the cap when a cap is being applied to a can. When the sizes are made to flt properly, the cushion ll provides a desirable slight yielding of interior surface of flange, which affords an easy reception of the can rim, yet there is no apparent looseness which might be obiectionableas giving an initial impression that the cap would not constitute a sufllciently tight closure. The cap may be easily rotated on the can when the can rim is only slightly within the flange. But, as the cap is pressed further home, more and more of the cushion l6 grips the can rim, with the creases 20 contributing to the gripping action until, when the cal) is say two-thirds of the way to its seat, the can rim will be gripped so tightly that it cannot easily be rotated by hand. And when the cap is fully seated the grip becomes still stronger. Liquid cannot escape between the flange and the can rim.

It-is important in containers of this sort that the cap shall be tight even though a heaping of contents shall prevent the cap from being fully seated. The cap closure of the invention effectively provides for such a contingency.

Heretofore it has been an unsolved problem to provide for a harmless escape of gases which may be entrapped within the container, as air when the cap is being put on, or which may be released or generated by contents. A considerable body of air, between the disk and the edges of the flange, is bound to be trapped under the cap as it is applied. With prior constructions this air has had to escape around'the flange. In order for it so to escape, a person has had to take pains to seat the cap gently. If forced on suddenly there has been'the danger that contents, especially liquid,

might .be forced out through thebottom annular seal, or the bottom itself be driven out.

The pruent invention provides for ventins these interior gases harmlessly through the cap flange wall, without risk of loss of liquid through the vent. To this end the in-turned portion I of the flange has its inner edge tucked loosely into the interior annular crevice or groove 24 at the disk crimp ll. Preferably the tucked-in edge will have been preliminarily compressed or beveled as at II to facilitate passage of gas around it and into the annular cylindrical crack 28 between the inner and outer thicknesses of flange walls. From this crack II the gases may escape to atmosphere throush one or more slits ll in the outerthickness of the flange. The fluidity of gases permitsthemtotakethe easiest courseout; andthe pathtocrackflandthencethroughaslit8lis that easiest course, yet this path is suiilciently mtrietedbythepressureoftheinner uponthe sothat gas will pass out only when a little pressure, and atmospheric air flnds diilicultyinentering. lheventis always availableincasegasesmaybegenemtedbycontainer eontmts.

Ineertamusesofcapclomra'ofthisgeneral may not be easily removed.

The present invention lendsitself admirably'to this situation. The in-turnedthickness of flange wall presents an annular edge interiorly which may constitute a seat for a closure disk II, as seen at Figure 3. The crimp It in this case may be a mere inward roll of the tubular stock, holding the disk to its said seat. Such a cap may not be liquid tight, but is suitable for the mentioned containers for ice cream. And the disk l2 easily may be disengaged from its flange and be lifted out from its flange with asuitable'sharptool. And the cap flange continues on the rim of the container, and may be forced down over the rim until the in-turned portion of the flange is seated on 2 the edge of the rim of the container body, reenforcing that rim.

It is also a feature of the invention that a desired aspect of general cylindricality is preserved for a capped can, which is made to have more finish and distinctiveness than some cans of the general sort heretofore available.

The improvement in the container body by making its wall double thick, Figure 1, turns the raw edge down into the crevice at the bottom of the container body ID, as described for the cover cap. The body wall thus has the same surface material outside and inside, and, in eifect, has no raw edge whatever. The rumpled aspect of surface illustrated and described with reference to the flange of the cover can be removed from the body interior by suitably smoothing the material. Containers used for food, in addition to being pure, strong and sound, must also have outside and inside finish of inviting aspect. By this construction one side of the paper stock from which the wall is made need not have a finished surface. This freedom gives opportunity for using stock which has, on its face that is to be doubled into the middle, out of sight, som useful material which may be less sightly than would meet the standard of flnishrequired on an exposed interior surface. It may, for example, be a heat-insulating material, to make a cup comfortable for holding a hot drink in the hand; or

5 a strengthening material, or a structurally suitable but less expensive body material. Southern kraft paper, strong, useful and cheap, but not pleasing to the sight, is an illustration. If it be desired to use for insulation a bright metal foil,

as aluminum foil, the low coefficient of heat loss by radiation may best be made available by inturning with a die that leaves the in-turned thickness at a slight distance from the outer thickness, even though the gap between thicknesses be only microscopic. The cover for such a body may have either-' the double thick flange herein illustrated, or any ordinary single thick flange with raw edge of the type hitherto in ordinary use.

The constructing of the body wall double thicki" with flnished rounded top edge and without any The cap flange, however, 7

single service and wastage, as paper'containers' have hitherto been designed.

I claim as my invention: 7

LA closure cap of paper for a container, corn-v prising a disk with annular, double-sheet-thick 5 cylindrical flange whose inner limb is an integral continuation of the outer limb, turned inward and laid against said outer limb; there being a thin passage, around the end of said inturned limb of flange, to the annular crack between the .two 10 limbs of flange, and a vent through the outer limb of the flange, whereby gases under pressure within a capped container may escape toatmosphere.

2. A closure cap of paper for a container, com- 15 prising a disk with annular, double-sheet-thick cylindrical flange whose inner limb is an integral continuation of the outer limb, turned inward and laid against said outer limb; said disk pressure within a capped container may escape to said vent.

3. A combination of container body, closure '30 disk therefor, and flange; wherein the flange combines with both disk and body to make a closure for the container when the cap is on, and

' is readily separable from the disk to remain combined with the body as a reinforcement which 35 may be seated on the edge of the rim of the body when the body is open; the said flange being of plural-ply helically-wound paper stock in-folded at one end to double-thickness and there providedwith an in-face for fltting the container; 40

- and being in-turned at its other end for engaging axially outside of the disk, this engagement being one at which the disk is by upward pull easily separable from the in-turned flange; and the said in-face and the out-face of the container 45 both being free from interfering projections, so that the one is free to slip over the other from the position of normal closure; whereby when the disk is removed from the flange, the cap being on the body, the flange can be slipped down 50 over the container until the in-turned portion of the flange is seated on the edge of the containerbody.

4. A combination of cylindrical container body, closure disk therefor, and cylindrical flange; 55 wherein the flange combines with both disk and body to make a cap closure for the container when the cap is on; means at said flange for venting air trapped within the cap closure; the said flange having an inner face for fitting the con- 60 tainer, and being in-turned for engaging outside of the disk, in direction parallel to the axis; the said disk at its margin having an annular groove in its upper face, in which groove the said inturned portion of flange engages; the marginal 6:, face of the disk under said groove constituting a prominent annular bead, interiorly of the cap at the juncture of disk and flange, for resting on the top edge of the container, thereby to space 

